Prosthesis delivery systems and methods

ABSTRACT

Apparatus and method deliver a prosthesis into a hollow body organ or blood vessel. The systems and methods make use of a catheter. A carrier on the distal end of the catheter is sized and configured to carry the prosthesis. A release mechanism and an enclosure mechanism on the distal end are operable to retain and enclose the prosthesis on the carrier. The release mechanism and the enclosure mechanism are also operable to selectively expose and release the prosthesis from the carrier for deployment in the hollow body organ or blood vessel.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/692,283 filed 23 Oct. 2003, now U.S. Pat. No. 7,147,657, which inturn claims the benefit of U.S. Provisional patent application Ser. No.60/488,753, filed Jul. 21, 2003, and entitled “Endoprosthesis DeliverySystems and Methods.”

FIELD OF THE INVENTION

The invention relates generally to the delivery of a prosthesis to atargeted site within the body, e.g., for the repair of diseased and/ordamaged sections of a hollow body organ and/or blood vessel.

BACKGROUND OF THE INVENTION

The weakening of a vessel wall from damage or disease can lead to vesseldilatation and the formation of an aneurysm. Left untreated, an aneurysmcan grow in size and may eventually rupture.

For example, aneurysms of the aorta primarily occur in abdominal region,usually in the infrarenal area between the renal arteries and the aorticbifurcation. Aneurysms can also occur in the thoracic region between theaortic arch and renal arteries. The rupture of an aortic aneurysmresults in massive hemorrhaging and has a high rate of mortality.

Open surgical replacement of a diseased or damaged section of vessel caneliminate the risk of vessel rupture. In this procedure, the diseased ordamaged section of vessel is removed and a prosthetic prosthesis, madeeither in a straight of bifurcated configuration, is installed and thenpermanently attached and sealed to the ends of the native vessel bysuture. The prosthetic prosthesis for these procedures are usuallyunsupported woven tubes and are typically made from polyester, ePTFE orother suitable materials. The prosthesis are longitudinally unsupportedso they can accommodate changes in the morphology of the aneurysm andnative vessel. However, these procedures require a large surgicalincision and have a high rate of morbidity and mortality. In addition,many patients are unsuitable for this type of major surgery due to otherco-morbidities.

Endovascular aneurysm repair has been introduced to overcome theproblems associated with open surgical repair. The aneurysm is bridgedwith a vascular prosthesis, which is placed intraluminally. Typicallythese prosthetic prostheses for aortic aneurysms are delivered collapsedon a catheter through the femoral artery. These prostheses are usuallydesigned with a fabric material attached to a metallic scaffolding(stent) structure, which expands or is expanded to contact the internaldiameter of the vessel. Unlike open surgical aneurysm repair,intraluminally deployed prostheses are not sutured to the native vessel,but rely on either barbs extending from the stent, which penetrate intothe native vessel during deployment, or the radial expansion force ofthe stent itself is utilized to hold the prosthesis in position. Theseprosthesis attachment means do not provide the same level of attachmentwhen compared to suture and can damage the native vessel upondeployment.

SUMMARY OF THE INVENTION

One aspect of the invention provides apparatus and methods fordelivering a prosthesis into a hollow body organ or blood vessel. Thesystems and methods include a catheter that is sized and configured forintroduction into the hollow body organ or blood vessel. A carrier onthe distal end of the catheter is sized and configured to carry theprosthesis. A release mechanism on the distal end is operable to retainthe prosthesis on the carrier. The release mechanism is also operable toselectively release the prosthesis from the carrier for deployment inthe hollow body organ or blood vessel. An enclosure mechanism on thedistal end is operable to enclose the prosthesis on the carrier. Theenclosure mechanism is also operable to selectively expose theprosthesis on the carrier, to thereby enable the release of theprosthesis from the carrier in response to selective operation of therelease mechanism, which can occur separate from the operation of theenclosure mechanism or in conjunction with the enclosure mechanism. Thesystems and methods include at least one actuator, which is coupled tothe release mechanism and the enclosure mechanism, to selectivelyoperate the release mechanism and the enclosure mechanism, eitherseparately or in conjunction.

Other features and advantages of the invention shall be apparent basedupon the accompanying description, drawings, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be understood from the following detailed descriptionof preferred embodiments, taken in conjunction with the accompanyingdrawings, wherein:

FIG. 1A is a perspective view of a prosthesis delivery catheter embodiesfeatures of the invention.

FIG. 1B is an enlarged perspective view, with portions broken away andin section, of the distal end of the prosthesis delivery catheter shownin FIG. 1A.

FIG. 2 is a perspective view of the prosthesis delivery catheter shownin FIG. 1A, being positioned within an abdominal aortic aneurysm.

FIG. 3 is a perspective view of a straight endovascular prosthesis afterdeployment by the prosthesis delivery catheter shown in FIG. 1A.

FIG. 4 is a perspective view of a bifurcated endovascular prosthesisafter deployment by the prosthesis delivery catheter shown in FIG. 1A.

FIG. 5A is an enlarged perspective view, with portions broken away andin section, of the inner assembly which is located in the distal end ofthe prosthesis delivery catheter shown in FIG. 1A.

FIG. 5B is an enlarged perspective view, with portions broken away andin section, of the inner assembly which is located in the distal end ofthe prosthesis delivery catheter shown in FIG. 5A, showing a prosthesisretained in a collapsed condition by restraining means prior todeployment.

FIG. 5C is an enlarged perspective view, with portions broken away andin section, of the inner assembly which is located in the distal end ofthe prosthesis delivery catheter shown in FIG. 5A, showing theprosthesis in an expanded condition after removal of the restrainingmeans.

FIG. 6 is a side view, with portions broken away and in section, of theprosthesis delivery catheter shown in FIG. 1A, showing the catheterretaining a prosthesis in a collapsed condition prior to deployment, theouter sheath being shown in an advanced position over the prosthesis.

FIG. 7 is a side view, with portions broken away and in section, of theprosthesis delivery catheter shown in FIG. 6, showing the catheterretaining a prosthesis in a collapsed condition prior to deployment, theouter sheath being shown in a position withdrawn from the prosthesis.

FIG. 8 is a side view, with portions broken away and in section, of theprosthesis delivery catheter shown in FIG. 7, showing the catheterretaining a prosthesis in a collapsed condition prior to deployment,with the pull wire still advanced to restrain radial expansion of theprosthesis.

FIG. 9 is a side view, with portions broken away and in section, of theprosthesis delivery catheter shown in FIG. 8, showing the prosthesis ina radially expanded condition after actuation of the pull wire to removethe restraining means.

FIG. 10 is a side view, with portions broken away and in section, of theprosthesis delivery catheter shown in FIG. 9, showing the withdrawal ofthe catheter from the prosthesis after its deployment.

FIG. 11A is a simplified side view of the distal end of the prosthesisdelivery catheter shown in FIG. 5B, with the outer sheath removed,showing the releasing means retaining the prosthesis in a restrainedcondition.

FIG. 11B is an end section view of the distal end of the prosthesisdelivery catheter shown in FIG. 11A, taken generally along line 11B-11Bin FIG. 11A.

FIG. 11C is a simplified side view of the distal end of the prosthesisdelivery catheter shown in FIG. 5B, with the outer sheath removed,showing an alternative embodiment of a restraining means for maintainingthe releasing means in a desired orientation while retaining theprosthesis in a restrained condition.

FIGS. 12A and 12B are simplified side views of the distal end of theprosthesis delivery catheter shown in FIG. 5B, with the outer sheathremoved, showing other alternative embodiments of a restraining meansfor maintaining the releasing means in a desired orientation whileretaining the prosthesis in a restrained condition, without relianceupon the catheter tip component.

FIGS. 13A and 13B are simplified side views of the distal end of theprosthesis delivery catheter shown in FIG. 5B, with the outer sheathremoved, showing other alternative embodiments of a restraining meansfor maintaining the releasing means in a desired orientation whileretaining the prosthesis in a restrained condition, without relianceupon a tubular sleeve carried by the central shaft.

FIGS. 14A and 14B are simplified side views of the distal end of theprosthesis delivery catheter shown in FIG. 5B, with the outer sheathremoved, showing other alternative embodiments of a releasing means witha cutting element for selectively releasing the prosthesis for use,together with an associated restraining means for maintaining thereleasing means in a desired orientation for operation.

FIGS. 15A and 15B are simplified side views of the distal end of theprosthesis delivery catheter shown in FIG. 5B, with the outer sheathremoved, showing other alternative embodiments of a releasing means witha wedge element for selectively releasing the prosthesis for use,together with an associated restraining means for maintaining thereleasing means in a desired orientation for operation.

DETAILED DESCRIPTION OF THE INVENTION I. Prosthesis Delivery Catheter

FIGS. 1A and 1B show a prosthesis delivery catheter 10. The purpose ofthe catheter 10 is to (i) contain and/or restrain a prosthesis 14 priorto its deployment (see FIG. 1B), (ii) deliver the prosthesis 14 throughthe vasculature to a desired location within the body, e.g., a hollowbody organ or a blood vessel (see FIG. 2), and (iii) controllably deploythe prosthesis 14 in the desired location (see FIG. 3).

In the illustrated arrangement (see FIG. 3), the prosthesis 14 takes theform of an endovascular, self-expanding stent prosthesis. In thisrespect, the prosthesis or prostheses 14 may have a wide variety ofconventional configurations. It can typically comprise a fabric or someother blood semi-impermeable flexible barrier which is supported by astructure formed by stents 48. The stent structure can have anyconventional stent configuration, such as zigzag, serpentine, expandingdiamond, or combinations thereof. The stent structure may extend theentire length of the prosthesis, and in some instances can be longerthan the fabric components of the prosthesis. Alternatively, the stentstructure can cover only a small portion of the prosthesis, e.g., beingpresent at the ends. The stent structure may have three or more endswhen it is configured to treat bifurcated vascular regions, such as thetreatment of abdominal aortic aneurysms, when the stent prosthesisextends into the iliac arteries. In certain instances, the stentstructures can be spaced apart along the entire length, or at least amajor portion of the entire length, of the stent-prosthesis, whereindividual stent structures are not connected to each other directly,but rather connected to the fabric or other flexible component of theprosthesis. Still, it is contemplated that the stent structures could beattached to one another at discrete locations, e.g., in the proximalneck region. Such stent structures could comprise individual stents thatare connected together when incorporated into the prosthesis, or stentsthat are manufactured in a joined condition prior to incorporation intothe prosthesis.

The stents 48 may be elastic, e.g., comprised of a shape memory alloyelastic stainless steel, or the like. For elastic, expanding typicallycomprises releasing the stent structure from a constraint to permit thestent structure to self-expand at the implantation site. As will bedescribed in greater detail, the catheter 10 places a sheath over thestent structure, in combination with releasable restraining meanscoupled to the stent structure, to maintain the stent structure in aradially reduced configuration during passage into the body. In thisarrangement, self-expansion of the stent structure is achieved bypulling back on the sheath and release of the restraining means, topermit the stent structure to assume its larger diameter configuration.

Alternatively, the stent structure may be formed from a malleablematerial, such as malleable stainless steel of other metals. Expansionmay then comprise applying a radially expansive force within thestructure to cause expansion, e.g., inflating a delivery catheter withinthe stent structure in order to affect the expansion. In thisarrangement, the positioning and deployment of the endoprosthesis can beaccomplished by the use of an expansion means either separate orincorporated into the deployment catheter. This will allow theendoprosthesis to be positioned within the vessel and partially deployedwhile checking relative position within the vessel. The expansion can beaccomplished either via a balloon or mechanical expansion device.Additionally, this expansion stabilizes the position of theendoprosthesis within the artery by resisting the force of blood on theendoprosthesis until the endoprosthesis can be fully deployed. Still,alternatively, the stent structure may comprise a combination of aself-expanding stent and a malleable stent structure.

In the illustrated embodiment (see FIG. 2), the catheter 10 is shown itis being positioned over a guidewire 12 in a body lumen. The catheter 10carries the prosthesis 14 in a radially reduced configuration to atargeted site. At the targeted site, the catheter 10 releases theradially reduced prosthesis 14, which expands radially (see FIG. 3).After partial or complete expansion or deployment of the prosthesis 14,one or more fasteners are desirably introduced by a fastener attachmentassembly to anchor the prosthesis 14 in place. Further details of thefastener attachment assembly can be found in U.S. patent applicationSer. No. 10/307,226, filed Nov. 29, 2002, which is incorporated hereinby reference.

The prosthesis 14 can be sized and configured to be either straight orbifurcated form. FIG. 3 depicts a completely deployed straightprosthesis 14. FIG. 4 depicts a completely deployed bifurcatedprosthesis.

For the purposes of illustration, FIG. 2 shows the targeted site asbeing within an abdominal aortic aneurysm. Of course, the targeted sitecan be elsewhere in the body.

As shown in FIGS. 1A and 1B, the catheter 10 comprises an inner assembly16, an outer sheath 18, and a handle assembly 20. These components willnow be individually described in greater detail.

A. The Inner Assembly

In the illustrated embodiment (see FIG. 5A), the inner assembly 16comprises a central shaft 22, which functions as a carrier for theprosthesis. The inner assembly also includes a catheter tip component24, a releasing means or mechanism 28 for retaining at least a portionof the prosthesis 14 in a radially compressed condition prior todeployment, a retaining means or mechanism 26 for maintaining thereleasing means 28 in a desired relationship with the central shaft 22during use, and a spacer 30.

In the embodiment shown in FIG. 5A, the central shaft 22, the retainingmeans 26, the releasing means 28, and the spacer 30 are located withinthe confines of the outer sheath 18. In this respect, the outer sheath18 functions as an enclosure for the prosthesis on the carrier. In thisarrangement, the catheter tip component 24 is attached the distal end ofthe central shaft 22, and the distal end of the outer sheath 18terminates adjacent the catheter tip component 24. Thus, the cathetertip component 24 extends outward beyond the outer sheath 18. The centralshaft 22, the releasing means 28, and the outer sheath 18 connect to thehandle assembly 20 at the proximal end of the catheter 10 (see FIG. 1A).In use (see FIG. 5B), the prosthesis 14 is contained in a cavity 32defined between the central shaft 22 and the outer sheath 18 in thedistal section of the catheter 10 (this arrangement is also shown inFIG. 1B).

The central shaft 22 extends from the handle assembly 20 (see FIG. 1A)to the catheter tip component 24. The central shaft 22 may be made,e.g., from stainless steel or other suitable medical materials includingother metals or polymers. The central shaft 22 desirably has at leastone lumen 36 (see FIG. 5A), with an inner diameter between 0.010 and0.120 inches, preferably between 0.03 and 0.06 inches and mostpreferably between 0.04 and 0.05 inches.

As described, the central lumen 36 allows for the insertion of a guidewire 12 up to 0.038″ diameter. The catheter tip component 24 alsodesirably has at least one lumen 38 (see FIG. 5A) configured to alignwith at least one lumen within the central shaft 22. This lumen 38allows for the insertion of a guide wire 12 through the central shaft 22and through the catheter tip component 24 (see FIG. 2). Typically thislumen will have an inner diameter between 010 and 0.120 inches,preferably between 0.03 and 0.06 inches and most preferably between 0.04and 0.05 inches.

Preferably, the catheter tip component 24 is flexible and has a long,tapered distal end and a shorter, tapered proximal end. The maximumdiameter of the catheter tip component 24 is approximately the same asthe outside diameter of the distal end of the outer sheath 18. Thedistal end of the catheter tip component 24 provides a smooth taperedtransition from the lumen 38 containing the guide wire 12 to the distaledge of the outer sheath 18. This feature aids in catheter insertion andnavigation through tortuous anatomy over the guide wire 12. The taperedsection on the proximal end of the catheter tip component 24 preventsthe catheter tip component 24 from inadvertently engaging the prosthesis14, portions of the surrounding anatomy, or an introducer sheath or thelike during removal of the catheter 10 from the body.

Still referring to FIG. 5A, the retaining means 26 holds the releasingmeans 28 in a desired, close relationship with the central shaft 22. Theretaining means 26 orients the releasing means 28 along the axis to ofthe central shaft 22 and allows the releasing means 28 longitudinalmovement in this axis. In the embodiment shown in FIGS. 5A, 5B, and 5C,the retaining means 26 includes a small hole or recess 40 in theproximal end of the catheter tip component 24 and a tube 56 having adiameter sufficiently large to accommodate both the central shaft 22 andthe releasing means 28. In the embodiment shown in FIGS. 5A, 5B, and 5C,the tube 56 of the retaining means 26 is located over the central shaft22 in alignment with and adjacent to the recess 40 on the catheter tipcomponent 24. The tube 56 is attached to the central shaft 22 in amanner in that retains a crescent shape lumen 42 between the tube 56 andthe central shaft 22. The releasing means 28 extends through this lumen42 and into the recess 40.

Returning to FIG. 5A, the spacer 30 provides support for the outersheath 18 and, by occupying space within the outer sheath 18, reducesthe amount of air entrapped within the catheter 10. The distal end ofthe spacer 30 desirably terminates adjacent the proximal end of theprosthesis 14 (as FIG. 5B shows). In this arrangement (see FIG. 5B), thecavity 32 containing the prosthesis 14 extends from the proximal end ofthe catheter tip component 24 to the distal end of the spacer 30. AsFIG. 5A shows, the spacer 30 is positioned over the central shaft 22 andreleasing means 28 and the proximal end of the spacer 30 is connected tothe handle assembly 20. Typically, the spacer 30 can have an outerdiameter slightly less than the inner diameter of the outer sheath 18.The spacer 30 can comprise a single lumen or an array of multiple lumensfor passage of the various components within the spacer 30.

The releasing means 28 holds the prosthesis 14 in a desiredconfiguration prior to deployment (see FIG. 5B) and selectively releasesthe prosthesis 14 for deployment (see FIG. 5C). In the illustratedembodiment, the proximal end of the releasing means 28 is connected toan actuator or control button or knob 46 in the handle assembly 20 (seeFIG. 1A). As FIG. 5B shows, the releasing means 28 extends along theoutside of the central shaft 22, through the inside of the spacer 30,and continues distally through the inside of the prosthesis 14. Thereleasing means 28 passes through the prosthesis 14 and the retainingmeans 26.

As FIG. 5B best shows, the prosthesis 14 is retained by the releasingmeans 28 along the central shaft 22 in the cavity 32, which extendsbetween the proximal end of the catheter tip component 24 and the distalend of the spacer 30. In the illustrated embodiment, the releasing means28 includes a wire 58 that extends along the central shaft 22. Thedistal end of the wire 58 passes through the crescent shape lumen 42 ofthe retaining means 26, and is ultimately captured in the hole or recess40 of the retaining means 26 in the proximal end of the catheter tipcomponent 24. The distal end of the wire 58 is thereby kept in a desiredrelationship along the central shaft 22. The proximal end of the wire 58is coupled to the control button 46, such that fore and aft movement ofthe button 46 advances the wire 58, respectively, distally andproximally.

As FIG. 5B shows (and which is further shown in more schematic form inFIGS. 11A, 11B, and 11C), the retaining means 28 includes sutures 44and/or equivalent structures, which are attached to one or more stents48 on the prosthesis 14. The sutures 44 are, in turn, looped around thewire 58 of the releasing means 28, when the wire 58 is in itsdistal-most position, as FIG. 5B shows. Proximal advancement of the wire58 (using the control button 46) withdraws the wire 58 from the sutureloops 44, as FIG. 5C shows.

In the illustrated embodiment (see FIG. 5B as well as FIGS. 11A, 11B,and 11C), the suture loops 44 are attached to one or more stents 48 atthe distal end of the prosthesis 14. It should be appreciated, however,that suture loops 44 could be attached to stents 44 elsewhere in theprosthesis 14, and/or the other components of the prosthesis 14 as well.

The suture loops 44 and wire 56 of the embodiment of the releasing means28 just described retain the prosthesis 14 to the central shaft (seeFIG. 5B). The suture loops 44 and the wire 56 keep the prosthesis 14from moving proximally as the outer sheath 18 is retracted. Thereleasing means 28 also keeps the stents 48 that are coupled to thesuture loops 44 in a radially compressed condition as the outer sheath18 is removed. The suture loops 44 and wire 56 prevent the distal end ofthe prosthesis 14 from self-expanding until the releasing means 28 hasbeen withdrawn. In the illustrated embodiment, the withdrawal of thereleasing means 28 is accomplished by operating the control button 46 tomove the wire 58 proximally, withdrawing the wire 58 from the hole orrecess 40 and away from the suture loops 44. Once the releasing means 28is withdrawn, the restrained components of the prosthesis 14 are freedto self expand, as FIG. 5C shows.

As illustrated and described, the releasing means 28 is coupled to onerestrained component of the prosthesis 14. It should be appreciated,however, that the releasing means 28 can be coupled to the prosthesis 14at two or more restrained regions, so that withdrawal of the releasingmeans 28 frees the prosthesis at two or more restrained regions. Itshould also be appreciated that the releasing means 28 can comprise morethan a single releasing element. For example, multiple, individualreleasing wires 58 could be coupled to the prosthesis 14 at differentregions, so that release of separate regions of the prosthesis 14 can beindividually controlled.

B. The Outer Sheath

The outer sheath 18 also serves to restrain the stents 48 on theprosthesis 14 from expanding and allows for a control deployment of theprosthesis 14 within the body. In the illustrated arrangement, the outersheath 18 is connected to an actuator or a collar or knob 50 on thehandle assembly 20. As FIG. 5A shows, the outer sheath 18 extendsdistally over the spacer 30 and prosthesis 14 and terminates adjacentthe proximal and of the catheter tip component 24. Typically, the outersheath 18 can be made of a polymer tube and be free of structuralreinforcement.

In the illustrated embodiment (see FIG. 5A), the outer sheath 18 istapered due to the difference in outer diameters of the catheter tipcomponent and the spacer 30. The larger diameter of the outer sheath 18is intended to contain the main body of the prosthesis 14 and thesmaller diameter would contain the leg portion or portions of theprosthesis 14, if present (as in the embodiment shown in FIG. 4). Thesmaller diameter continues proximally to the handle assembly 20. Thistapered feature of the outer sheath 18 also allows for better bloodcirculation passed the catheter.

C. Handle Assembly

The handle assembly 20 provides the operator with longitudinal androtational control of the catheter 10 within the body and providesaccess to the actuator or control means for deploying the prosthesis 14.

In the illustrated embodiment, the handle assembly 20 comprises a handlebody 52 and the sliding knob or collar 50 which is connected to theproximal and the of the outer sheath 18, and the knob or button 46 whichis attached to proximal end of the releasing means 28. In theillustrated embodiment, the central shaft 22 is captured within thehandle and has a guide wire receiving luer 34 connected to its proximalend, which is located at the proximal end of the handle assembly 20.This design prevents the position of the prosthesis 14 from movingrelative to the handle body 52 while the outer sheath 18 is retracted.

To withdraw the outer sheath 18 from the prosthesis 14 (see FIGS. 6 and7), the sliding knob 50 is moved proximally until the distal end of theouter sheath 18 is free of the prosthesis 14 (see FIG. 8). The portionor portions of the prosthesis 14 that are not coupled to the releasingmeans 28 (which, in the illustrated embodiment comprise the proximalregion of the prosthesis 14) are free to self-expand, as FIG. 8 shows.However, the portions of the prosthesis 14 that are coupled to thereleasing means 58 (which, in the illustrated embodiment comprise thedistal region of the prosthesis 14) are still restrained fromself-expansion, despite withdrawal of the outer sheath 18, as FIG. 8also shows. The stent structure of the prosthesis 14 is thereby keptrestrained closely against the central shaft tube 22 while the outersheath 18 is retracted. The retaining means 26 prevents the prosthesis14 from moving relative to the central tube 22 during retraction of theouter sheath 18, which potentially minimizes blood flow through theprosthesis 14 during the deployment process. Furthermore, as described,the prosthesis 14 is not “pushed out” of the catheter. The prosthesis 14therefore need not have longitudinal stiffness or a stent structure witha “spine”.

To withdraw the releasing means 28 (see FIGS. 8 and 9), the slidingbutton 46 is moved proximally until the distal end of the releasingmeans 28 is withdrawn from the restraining means 26. The prosthesis isthereby free to fully self-expand, as FIG. 9 and FIG. 5C show. Asdescribed, the prosthesis 14 is not released immediately from distal endto proximal end as the sheath 18 is withdrawn. As the outer sheath 18 isretracted, the prosthesis 14 is pulled in tension, which “stretches” theprosthesis to its proper length and stent spacing. The distal stent orstents 48 are released in a secondary operation, which follows thewithdrawal of the outer sheath 18 (as shown in FIGS. 5C, 8, and 9).Final placement of distal end of the prosthesis 14 can thereforecomprise a final step in the deployment process.

It should be appreciated that the knob 50 can comprise a separatecomponent that is not part of the handle assembly 20, i.e., on the outersheath 18.

II. Use of the Prosthesis Delivery Catheter

During use, the catheter 10 is navigated over the guide wire 12 to thedesired location within the body (as FIG. 2 shows). In the illustratedembodiment, deployment of the prosthesis 14 is achieved in a two stepprocess. First, by pulling the knob or collar 50 on the handle assembly20 proximally, the outer sheath 18 is retracted and exposes theprosthesis 14 (as FIGS. 6 and 7 show). The unrestrained portion orportions of the prosthesis 14 self-expand, as FIG. 8 show. As FIGS. 6and 7 show, during retraction of the outer sheath 18, the prosthesis 14maintains its position relative to the central shaft 22 due to thereleasing means 28 connected to the prosthesis 44.

In the second step of the deployment process, following the withdrawalof the outer sheath 18, the control button or knob 46 on the handleassembly 20 is moved proximally (see FIGS. 8 and 9). This causes thedistal end of the releasing means 28 to be withdrawn and allows therestrained stent or stents 44, and the prosthesis 14 as a whole, toself-expand radially (as FIGS. 5C and 9 show). The prosthesis 14enlarges to contact the internal walls of the vessel or hollow bodyorgan, as FIG. 3 shows. The catheter 10 can then be withdrawn (as FIG.10 shows).

It should be appreciated that the withdrawal of the outer sheath 18 andthe withdrawal of the releasing means 28 can be accomplished in a singlestep process. In this arrangement, a single activation mechanism can bejointly coupled to the outer sheath 18 and the releasing means 28, sothat the outer sheath 18 and releasing means 28 are withdrawn in asingle step.

III. Alternative Embodiments

In the embodiment shown in FIGS. 11A to 11C (as already described), thedistal end of a movable component of the releasing means 28 (e.g., thewire 58) extends along the central shaft 22 in a manner prescribed andcontrolled by the restraining means 26, i.e., between a tube 56 carriedby the central shaft 22 and a recess 40 located in the proximal end ofthe catheter tip component 24. It is in the region between the tube 56and the recess 40, that a stationary component of the releasing means28, which is attached to the prosthesis 14 (e.g., the suture loops 44),is operatively coupled to the movable component of the releasing means28. Movement of the movable component 58 out of this region releases thestationary component 44. The overall objective of the restraining means26 is achieved: the restraining means 26 serves to maintain the movablecomponent 58 of the releasing means 28 in a desired operative alignmentwith the central shaft 22, as well as in a desired operativerelationship with the stationary component 44 of the releasing means 28,such that quick and certain release of the prosthesis 14 occurs.

The releasing means 28 and the restraining means 26 can be variouslyconstructed to meet this objective. For example, in the alternativeembodiment shown in FIG. 12A, the distal end of the movable component 58of the releasing means 28 extends along the central shaft 22 in a mannerprescribed and controlled by the restraining means 26, i.e., betweenadjacent, spaced apart tubes 60A, and 60B, without dependence uponadditional support by the catheter tip component 24. Each tube 60A and60B surrounds the central shaft 22 in the same fashion as the singletube 56 shown in FIGS. 11A to 11C. The movable component 58 of thereleasing means 28 is held in the region between the two tubes 60A and60B in operative association with the stationary component 44 of thereleasing means 28, and can be quickly and certainly withdrawn from thisregion to release the prosthesis 14. In a similar alternativearrangement (see FIG. 12B), the distal end of the movable component 58of the releasing means 28 extends along the central shaft 22 betweenadjacent, spaced apart external tubes 62A and 62B, again withoutdependence upon additional support by the catheter tip component 24. InFIG. 12B, the tubes 62A and 62B project along the exterior of thecentral shaft 22, but do not surround it. Still, it should beappreciated that a single external support tube like tube 62A or 62Bcould, alternatively, be used in a hybrid combination with the recess 40in the catheter tip component 24, if desired.

In another illustrative, alternative embodiment (see FIG. 13A), thedistal end of the movable component 58 of the releasing means 28 extendswithin a lumen in the 66 central shaft 22, exiting through an aperture64 in the shaft 22 and into a recess 40 in the catheter tip component24. The movable component 58 of the releasing means 28 is held in theregion between the aperture 64 and the recess 40 in operativeassociation with the stationary component 44 of the releasing means 28,and can be quickly and certainly withdrawn from this region to releasethe prosthesis 14. In a similar alternative arrangement (see FIG. 13B),the distal end of the movable component 58 of the releasing means 28extends within a lumen 68 the central shaft 22 between adjacent, spacedapart apertures 70 and 72. The movable component 58 exits the aperture72 and enters a recess 40 in the catheter tip component 24. The movablecomponent 58 of the releasing means 28 is held in the region between theaperture 72 and the recess 40 in operative association with thestationary component 44 of the releasing means 28, and can be quicklyand certainly withdrawn from this region to release the prosthesis 14.

In yet another illustrative, alternative embodiment (see FIGS. 14A and14B), the restraining means 26 includes a single tube 74 carried by thecentral shaft 22, through which the movable component 58 of thereleasing means 28 passes. The tube 74 can comprise a surrounding tubeof the type shown in FIG. 12A (as FIGS. 14A and 14B show) or an externaltube of the type shown in FIG. 12B.

In this arrangement, the releasing means 28 includes a suture loop 76carried by the proximal end of the catheter tip component 24 and acutting element 78 carried on the distal end of the movable component 58of the releasing means 28. The suture loop 76 passes through the sutureloops 44 on the prosthesis 14, as well as through the cutting element78. The cutting element 78 on the distal end of the movable component 58of the releasing means 28 extends along the central shaft 22 in a mannerprescribed and controlled by the restraining means 26, i.e., through andbeyond the tube 74, and in operative association with the suture loops44 and 76, which, in this embodiment, comprise the stationary componentsof the releasing means 28. This occurs without dependence uponadditional support by the catheter tip component 24. Withdrawal of themovable component 58 moves the cutting element 78 through the sutureloop 76, cutting the suture loop 76 and releasing the prosthesis 14 (asFIG. 14B shows).

In yet another illustrative, alternative embodiment (see FIGS. 15A and15B), the restraining means 26 includes a single tube 80 carried by thecentral shaft 22, through which the movable component 58 of thereleasing means 28 passes. As the tube 74 shown in FIGS. 14A and 14B,the tube 80 can comprise a surrounding tube of the type shown in FIG.12A (as FIGS. 15A and 15B show) or an external tube of the type shown inFIG. 12B.

In this arrangement, the releasing means 28 includes a wedge element 84carried on the distal end of the movable component 58 of the releasingmeans 28. The wedge element 84 nests within a mating wedge surface 86formed in the proximal end of the catheter tip component 24. Advancementof the movable component 58 moves the wedge element 84 into theregistration within the wedge surface 86 (as FIG. 15A shows) and out ofregistration with the wedge surface 86 (as FIG. 15B shows). Thereleasing means 28 in this arrangement further includes alternativeembodiments of suture loops 82 or 82′, which are pinched between thewedge element 84 and the wedge surface 86 when the element 84 and thesurface 86 are in registration, as FIG. 15A shows. The embodiment of thesuture loop 82 comprises a closed loop 82 carried by a prosthesis stent48. The embodiment of the suture loop 82′ comprises an open loop 82′carried by the proximal end of the catheter tip component 24 and loopedthrough a prosthesis stent 48. When either embodiment of the suture loop82 or 82′ is pinched between the wedge element 84 and the indentedsurface 86, expansion of the prosthesis 14 is restrained (as FIG. 15Ashows). When the movable component 58 of the releasing means 28 isadvanced proximally, the wedge element 84 is freed from registrationwithin the wedge surface 86, freeing the loops 82 or 82′, therebyreleasing the prosthesis 14 for expansion, as FIG. 15B shows.

The preferred embodiments of the invention are described above in detailfor the purpose of setting forth a complete disclosure and for the sakeof explanation and clarity. Those skilled in the art will envision othermodifications within the scope and sprit of the present disclosure.

The above described embodiments of this invention are merely descriptiveof its principles and are not to be limited. The scope of this inventioninstead shall be determined from the scope of the following claims,including their equivalents.

1. An apparatus for delivering a prosthesis comprising a catheter sizedand configured for introduction into a hollow body organ or bloodvessel, the catheter having a distal end, a carrier on the distal endsized and configured to carry the prosthesis during introduction of thecatheter, a release mechanism on the distal end being operable to retainthe prosthesis on the carrier, the release mechanism also being operableto selectively release the prosthesis from the carrier for deployment inthe hollow body organ or blood vessel, wherein at least part of therelease mechanism is located inside of the prosthesis prior todeployment, an enclosure mechanism on the distal end being operable toenclose the prosthesis on the carrier, the enclosure mechanism alsobeing independently operable from said release mechanism to selectivelyexpose the prosthesis on the carrier, to thereby enable the release ofthe prosthesis from the carrier in response to selective operation ofthe release mechanism, and at least one actuator coupled to the releasemechanism and the enclosure mechanism to selectively operate the releasemechanism and the enclosure mechanism.
 2. The apparatus according toclaim 1, wherein the release mechanism comprises at least one sutureloop in contact with the prosthesis and a releasing wire, wherein thesuture loop is configured to prevent at least a portion of theprosthesis from self-expanding until the suture loop is no longer incontact with the releasing wire.